From: "Toke Høiland-Jørgensen" <toke@redhat.com>
To: Jamal Hadi Salim <jhs@mojatatu.com>,
John Fastabend <john.fastabend@gmail.com>,
Jesper Dangaard Brouer <jbrouer@redhat.com>,
"Karlsson, Magnus" <magnus.karlsson@intel.com>,
"Desouza, Ederson" <ederson.desouza@intel.com>
Cc: brouer@redhat.com,
"xdp-hints@xdp-project.net" <xdp-hints@xdp-project.net>,
Eelco Chaudron <echaudro@redhat.com>,
Andrii Nakryiko <andrii@kernel.org>,
"Fijalkowski, Maciej" <maciej.fijalkowski@intel.com>,
"Burakov, Anatoly" <anatoly.burakov@intel.com>,
tom Herbert <tom@sipanda.io>
Subject: [xdp-hints] Re: Basic/Dumb question WAS(Re: Re: XDP-hints via local BTF info
Date: Mon, 22 Nov 2021 14:59:16 +0100 [thread overview]
Message-ID: <87r1b8cmvf.fsf@toke.dk> (raw)
In-Reply-To: <bff218f8-2a98-f235-67fe-f1797eba4704@mojatatu.com>
Jamal Hadi Salim <jhs@mojatatu.com> writes:
> And it goes something like this:
>
> Why does the metadata have to go in the DMA descriptors?
> Our experience with the XDP metadata is: you start accessing
> that there is a performance penalty (extra cache miss(es)).
>
> Why is the metadata not encapped as part of the data? We
> dont have MTU issues on receive since that is entirely a local matter;
> meaning the hardware can expand the packet as much as it wants within
> the boundaries of alloced DMA buffer space and XDP and any other
> subsystem (TC for example) can take advantage of the metadata.
Once the hardware learns how to do that, this is absolutely the
direction we want to go in. But for existing stuff, the metadata is in
the descriptor and needs to be translated somehow...
-Toke
next prev parent reply other threads:[~2021-11-22 13:59 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-11-17 17:22 [xdp-hints] " Jesper Dangaard Brouer
2021-11-17 20:07 ` [xdp-hints] " Karlsson, Magnus
2021-11-17 22:48 ` Toke Høiland-Jørgensen
2021-11-18 8:05 ` Karlsson, Magnus
2021-11-18 14:30 ` Jesper Dangaard Brouer
2021-11-18 14:57 ` Karlsson, Magnus
2021-11-18 15:18 ` John Fastabend
2021-11-19 14:53 ` Toke Høiland-Jørgensen
2021-11-22 12:45 ` [xdp-hints] Basic/Dumb question WAS(Re: " Jamal Hadi Salim
2021-11-22 13:59 ` Toke Høiland-Jørgensen [this message]
2021-11-22 15:31 ` [xdp-hints] " Tom Herbert
2021-11-22 18:25 ` Toke Høiland-Jørgensen
2021-11-22 12:57 ` [xdp-hints] " Alexander Lobakin
2021-11-24 11:54 ` Jesper Dangaard Brouer
2021-11-25 20:04 ` Alexander Lobakin
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